Tris(disubstituted amino)sulfonium perfluorocarbanion salts

ABSTRACT

Tris(disubstituted amino)sulfonium perfluorocarbanion salts and process for their preparation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to tris(disubstituted amino)sulfoniumperfluorocarbanion salts and to process for the preparation thereof, thecarbanion salts being useful as polymerization catalysts and as reagentsfor preparing fluoro-organic compounds.

2. Background

Tris(dialkylamino)sulfonium (TAS) salts of the formula (R¹ R² N)(R³ R⁴N)(R⁵ R⁶ N)S⁶¹ X.sup.⊖ wherein each R is C₁₋₂₀ alkyl having at least twoα-hydrogen atoms and X is (CH₃)₃ SiF₂, Cl, Br, I, CN, NCO, NCS, NO₂ orN₃ are disclosed in U.S. Pat. No. 3,940,402. The TAS salts are solublein organic liquids and are useful as polymerization catalysts and asreagents for replacing various groups in organic compounds with thegroup X.

Chambers et al., J.C.S. Perkin I, 1980, 435-439, disclose thepreparation of fluorocarbanions by reacting CsF and selectedfluoroolefins in dimethylformamide (DMF), the olefins beingperfluorocycloalkene derivatives. The product anions are observed by ¹⁹F NMR spectroscopy and are trapped with bromine or chlorine to givebromo- or chloro-fluorocycloalkanes.

The preparation of solutions of N,N,N'N'-tetramethylformamidiniumperfluorocarbanions in DMF by reacting [(CH₃)₂ N]₂ C.sup.⊕ HF₂.sup.⊖ andbranched perfluoroolefins is disclosed by Delyagina et al., Izv. Akad.Nauk SSSR, Ser. Khim., No. 10, 2238-2243 (1981), English languagetranslation. The carbanions are characterized in solution by ¹⁹ F NMRspectroscopy and found to be stable at low temperature.

Young, Fluorine Chem. Rev., 1967, 1, 359-397, particularly pages360-366, 371-377 and 383-387, reviews perfluoroalkyl carbanionchemistry, in general, and the dimerization and polymerization ofolefins, in particular. The use of fluorocarbanions in nucleophilicdisplacements, particularly for fluoroalkyl iodide synthesis, isdiscussed in detail.

Brunskill et al., Chem. Communications, 1970, 1444-1446, disclose thefluoride ion-catalyzed oligomerization (dimerization and trimerization)of hexafluoropropene and the formation of heptafluoroisopropylcarbanion.

DETAILED DESCRIPTION OF THE INVENTION

For further comprehension of the invention, and of the objects andadvantages thereof, reference may be made to the following descriptionand to the appended claims in which the various novel features of theinvention are more particularly set forth.

The invention resides in tris(disubstituted amino)sulfoniumperfluorocarbanion salts of the formula ##STR1## wherein R¹ through R⁶,each selected independently, are C₁ -C₂₀ alkyl, each having at least 2alpha hydrogen atoms, or any or all of the pairs R¹ and R², R³ and R⁴,and R⁵ and R⁶, each pair selected independently, are --CH₂)₄ or --CH₂)₂CHY(CH₂)₂, wherein Y is hydrogen or methyl;

R_(f) ¹, R_(f) ² and R_(f) ³, each selected independently, are F, C₁₋₂₀perfluoroalkyl or C₄₋₁₂ perfluorocycloalkyl; and

R_(f) ⁴ is C₁₋₂₀ perfluoroalkyl or C₄₋₁₂ perfluorocycloalkyl; or

any one of the pairs R_(f) ¹ and R_(f) ², R_(f) ³ and R_(f) ⁴, R_(f) ¹and R_(f) ³, and R_(f) ² and R_(f) ⁴, taken together, is --CF₂)_(n)wherein n is an integer and is 2 to 6; or

each of the pairs R_(f) ¹ and R_(f) ² and R_(f) ³ and R_(f) ⁴, or eachof the pairs R_(f) ¹ and R_(f) ³ and R_(f) ² and R_(f) ⁴, takentogether, is --CF₂)_(n) wherein n, each selected independently, is aninteger and is 2 to 6.

The invention also resides in a process for the preparation of theperfluorocarbanion salts. The process comprises containing and reacting,in an inert solvent, the perfluoroolefin of the formula ##STR2## and thesulfonium salt of the formula [(NR¹ R²)(NR³ R⁴)(NR⁵ R⁶)]S.sup.⊕ (CH₃)₃SiF₂.sup.⊖. All symbols are as defined above.

Suitable solvents include any inert solvent, that is, a solvent thatwill dissolve the sulfonium salt without reacting with it. Examplesinclude nitriles, such as acetonitrile, propionitrile, and benzonitrile,and amines, such as pyridine and quinoline.

The reaction can be carried out at -100° to 100° C. Higher temperaturescan be used, but generally provide no advantage. The preferredtemperature range is -80° to 50° C.

Ambient pressure is preferred for the reaction because of convenience,but either subatmospheric pressure or superatmospheric pressure isoperable.

The reaction can be carried out with or without a solvent, although thepresence of a solvent is preferred. When a solvent is employed, thefluoroolefin and the sulfonium salt should be present in concentrationsof at least about 0.001 molar, preferably at least about 0.01 molar,more preferably at least about 0.1 molar. Either reactant can be inmoderate excess, but best yields are achieved when the reactants areused in approximately equimolar amounts. A large excess of eitherreactant may lead to undesirable further reaction of the desired productof the invention. However, in selected instances, such as thosedemonstrated in Utility Examples N and O, use of excess fluoroolefin toinduce further reaction may be desirable.

Either reactant can be added to the solvent first, followed by additionof the second reactant or both reactants can be added to the solventsimultaneously. Alternatively, either or both reactants can be preparedin situ in the solvent, reaction then taking place when both reactantsare present.

Many of the carbanion salts can be isolated as crystalline solids by theevaporation of the reaction solvent at reduced pressure. The isolablesalts contain tertiary carbanions which are cyclic, or acyclic anddevoid of branched α-carbon atoms. Salts which contain secondarycarbanions, or certain tertiary acyclic carbanions having branchedα-carbon atoms, may not be isolable. Such salts are exemplified inExamples 4-7 (infra). Those of Examples 4 and 5 can be identified insolution, for example, spectroscopically or by ¹⁹ F NMR, and useddirectly in subsequent reactions, as described hereinafter. Salts ofExamples 6 and 7 are not readily identifiable in solution, but can beused in subsequent reactions and can be unequivocally identified asintermediates to the products isolated.

Preferred carbanion salts of the invention are those wherein R_(f) ¹ isF, R_(f) ² is F or C₁₋₁₀ perfluoroalkyl, and R_(f) ³ and R_(f) ⁴ areeach CF₃. More preferred are the above salts wherein R¹ -R⁶ are each CH₃or the pairs R¹ and R², R³ and R⁴, and R⁵ and R⁶ are each --CH₂)₅. Mostpreferred salts are those wherein R_(f) ¹ is F, R_(f) ² is F, CF₃ or C₂F₅, R_(f) ³ and R_(f) ⁴ are each CF₃ and R¹ -R⁶ are each CH₃.

Preferred fluoroolefins for use in the invention process are thosewherein R_(f) ¹ is F, R_(f) ² is F or C₁₋₁₀ perfluoroalkyl, morepreferably F, CF₃ or C₂ F₅, and R_(f) ³ and R_(f) ⁴ are each CF₃.Preferred starting sulfonium salts are those wherein R¹ -R⁶ are eachCH₃, or the pairs R¹ and R², R³ and R⁴, and R⁵ and R⁶ are each --CH₂)₅.Most preferred starting sulfonium salts are those wherein R¹ -R⁶ areeach CH₃.

Examples of perfluorocarbanion salts of the invention, and the reactantsthat can be used to prepare them, are shown in the following table.

    __________________________________________________________________________       Reactants             Product                                              __________________________________________________________________________     ##STR3##                                                                                            ##STR4##                                                ##STR5##                                                                      ##STR6##                                                                                            ##STR7##                                                ##STR8##                                                                      ##STR9##                                                                                            ##STR10##                                               ##STR11##                                                                     ##STR12##                                                                                           ##STR13##                                              [(C.sub.2 H.sub.5).sub.2 N].sub.3 S.sup.⊕ F.sub.2 Si(CH.sub.3).sub.3.s    up.⊖                                                                   ##STR14##                                                                                           ##STR15##                                              [(CH.sub.3).sub.2 N].sub.3.sup.⊕S F.sub.2 Si(CH.sub.3).sub.3.sup..crcl    bar.                                                                                                 ##STR16##                                              __________________________________________________________________________

The carbanion salts of the invention are useful as intermediates in thesynthesis of fluorine-containing compounds. They show a high anionreactivity, and readily displace halogens (Cl, Br, I) or sulfonategroups (--OSO₂ F, --OSO₂ CF₃, --OSO₂ Ar) from organic compounds to formnew fluorine-containing organic compounds. They can also be reacted withhalogens (I₂, Br₂, Cl₂) to form the corresponding perfluoroalkylhalides. Many of the compounds that can be prepared from thesecarbanions are useful as solvents, dielectric liquids, radio-opaquediagnostic aids, drugs, and oxygen-carrying liquids for use in preparingartificial blood.

The carbanion salts of the invention are useful, per se, in theisomerization of fluoroolefins, as demonstrated by Utility Example O.The isolable tertiary carbanion salts of the invention also have utilityas polymerization catalysts, for example, in polymerization reactions ofthe group transfer polymerization type disclosed: (1) by Webster et al.in J. Am. Chem. Soc., 105 5706 (1983); and (2) in U.S. Pat. Nos.4,414,372 and 4,417,034, and in U.S. patent application Ser. Nos.549,408 and 549,409, wherein such processes one or more selected,α,β-unsaturated compounds are contacted under polymerizing conditionswith a selected silicon-, germanium- or tin-containing initiator and aselected Lewis acid or anion catalyst. More specific details may befound in the patents and patent applications, the disclosures of whichare hereby incorporated by reference. Utility Example M hereindemonstrates such utility.

The following list of compounds demonstrates the variety offluoro-organic compounds which can be prepared from the carbanion saltsof the invention:

(1) 2-Bromo-1,1,1,3,3,4,4,5,5,5-decafluoro-2-(trifluoromethyl)pentane(Utility Example C) and2-bromo-1,1,1,3,4,4,4-heptafluoro-2,3-bis(trifluoromethyl)butane(Utility Example K), are compounds which are useful as radio-opaqueagents for contrast enhancement of x-rays.

(2) Bromononafluorocyclopentane (Utility Example L) is useful as afire-extinguishing agent.

(3) Hexafluoropropylene trimers (Utility Example N) are useful as inertsolvents of low dielectric constant.

The carbanion salts of the invention, in contrast to those known in theart, are readily soluble in organic solvents, are stable, and undergo avariety of reactions with electrophiles to give new fluoro-organiccompounds. The tertiary salts are isolable as crystalline solids, arestable at elevated temperatures, and can be fully characterized by NMRspectroscopy.

In the following examples, temperatures are in degrees Celsius; ¹ H NMRspectroscopic data are recorded in ppm downfield from tetramethylsilanestandard; and ¹⁹ F NMR spectroscopic data are recorded in ppm downfieldfrom Freon®-11 internal standard. All reactants are known compoundswhich are commonly available. In Examples 1 to 6, fluorotrimethylsilaneis produced as a by-product.

EXAMPLE 1 Tris(dimethylamino)sulfonium1,1,1,3,3,3-Hexafluoro-2-(trifluoromethyl)-2-propanide

Octafluoroisobutylene, 14.8 g (0.074 mol), was slowly distilled into astirred solution of 20.3 g (0.074 mol) of tris(dimethylamino)sulfoniumdifluorotrimethylsilicate in 75 mL of dry acetonitrile cooled to 0°. Thereaction mixture was warmed to 25° and then evaporated to dryness underreduced pressure to give 24.4 g (86%) of tris(dimethylamino)sulfonium1,1,1,3,3,3-hexafluoro-2-(trifluoromethyl)-2-propanide as a white solid:m.p. 160°-164°; ¹⁹ F NMR (CD₃ CN) -45.0 ppm; ¹ H NMR (CD₃ CN) 2.88 ppmAnal. Calcd. for C₁₀ H₁₈ F₉ N₃ S: C, 31,33; N, 10.96. Found: C, 31.89; N11.05.

EXAMPLE 2 Tris(piperidino)sulfonium1,1,1,3,3,3-Hexafluoro-2-(trifluoromethyl)-2-propenide

Octafluoroisobutylene, 8.34 g (0.042 mol), was slowly distilled into astirred solution of 15.0 g (0.038 mol) of tris(piperidino)sulfoniumdifluorotrimethylsilicate in 50 mL of acetonitrile cooled to -10°. Thereaction mixture was warmed to 25° and then evaporated to dryness underreduced pressure. The residue was washed with dry ether and then driedto give 17.3 g (90%) of tris(piperidino)sulfonium1,1,1,3,3,3-hexafluoro-2-(trifluoromethyl-2-propenide as white crystals:m.p. 138°-142°; ¹ H NMR (CD₃ CN) δ 1.64 ppm (m, 18H), 3.21 ppm (m, 12H);¹⁹ F NMR (CD₃ CN) δ -42.5 ppm (s). Anal. Calcd. for C₁₉ H₃₀ F₉ N₃ S: C,45.32; H, 6.01. Found: C, 45.48; H, 6.17.

EXAMPLE 3 Tris(dimethylamino)sulfonium1,1,1,3,3,4,4,5,5,5-Decafluoro-2-(trifluoromethyl)-2-pentanide

1,1,1,3,4,4,5,5,5-Nonafluoro-2-trifluoromethyl-2-pentene (26.4 g, 0.088mol) was added to a solution of 22.0 g (0.08 mol) oftris(dimethylamino)sulfonium difluorotrimethylsilicate in 10 mL ofacetonitrile. The reaction mixture was stirred until it was homogeneous,and then evaporated to dryness under reduced pressure to give 36.0 g(94%) of tris(dimethylamino)sulfonium1,1,1,3,3,4,4,5,5,5-decafluoro-2-(trifluoromethyl)-2-pentanide: mp60°-70°; ¹⁹ F NMR (CD₃ CN) δ -41.1 ppm (t,t,J=19.4, 6.4 Hz, 6F), -80.2ppm (t, J=10.4 Hz, 3F), -91.7 ppm (well resolved multiplet, 2F), -125.3ppm (m, 2F); ¹ H NMR (CD₃ CN) δ 2.98 ppm (s). Anal. Calcd. for C₁₂ H₁₈F₁₃ N₃ S: C, 29.82; H, 3.75; F, 51.10; N, 8.69. Found: C, 29.43; H,3.87; F, 50.70; N, 8.77.

EXAMPLE 4 Tris(dimethylamino)sulfonium1,1,1,3,4,4,4-Heptafluoro-2,3-bis(trifluoromethyl)-2-butanide

A solution of tris(dimethylamino)sulfonium1,1,1,3,4,4,4-heptafluoro-2,3-bis(trifluoromethyl)-2-butanide inacetonitrile was prepared by dissolving 8.00 g (0.027 mol) oftetrakis(trifluoromethyl)ethylene in a solution of 7.40 g (0.027 mol) oftris(dimethylamino)sulfonium difluorotrimethylsilicate in 30 mL ofacetonitrile. The reaction was also repeated, using CD₃ CN andpropionitrile as solvents, to give solutions of the product in thesesolvents. ¹⁹ F NMR (propionitrile, -79.7°) δ -39.1 ppm (m, 6F), -71.5ppm (m, 6F) [the signal for the tertiary fluorine was too broad to beaccurately measured]; ¹⁹ F NMR (CD₃ CN, 25°) δ -58.1 ppm (1/2w=27 Hz)[all fluorines equivalent due to rapid exchange at this temperature].

EXAMPLE 5 Tris(dimethylamino)sulfonium1,2,2,3,3,4,4,5,5-Nonafluorocyclopentanide

A solution of tris(dimethylamino)sulfonium1,2,2,3,3,4,4,5,5-nonafluorocyclopentanide in acetonitrile was preparedby adding 15 g (0.071 mol) of perfluorocyclopentene to 21.4 g (0.078mol) of tris(dimethylamino)sulfonium difluorotrimethylsilicate in 100 mLof acetonitrile cooled to 0°. Solutions of the pentanide were alsoprepared in propionitrile and benzonitrile by a similar procedure. ¹⁹ FNMR (propionitrile) δ -79.4 ppm (m, 4F), -126.7 ppm (m, 4F) and -131.9ppm (m, 1F).

EXAMPLE 6 Tris(dimethylamino)sulfonium1-Perfluorocyclobutyl-1-perfluorocyclobutanide

A mixture of perfluorobicyclobutylene andperfluoro(1-cyclobutylcyclobutene) (2.0 g, 0.0062 mol) was addeddropwise to a solution of 1.67 g (0.0061 mol) oftris(dimethylamino)sulfonium difluorotrimethylsilicate in 20 mL ofacetonitrile at 0°. The reaction mixture was warmed to 25°, and thenevaporated to dryness under reduced pressure to give the carbanion saltas a colorless viscous liquid: ¹ H NMR (CD₃ CN) δ 2.85 ppm (s); ¹⁹ F NMR(CD₃ CN) δ -86.3 ppm (d, J=43 Hz, 4F atoms adjacent to anionic center),-156.2 ppm (broad, tertiary C-F), and 122-134 ppm (8F, unassigned).

Following are examples which demonstrate the utility of the compounds ofthe invention.

EXAMPLE A 2-Bromo-1,1,1,3,3,3-hexafluoro-2-(trifluoromethyl)propane

Bromine, 17.25 g (0.108 mol), was added dropwise at 0° to a solution oftris(dimethylamino)sulfonium1,1,1,3,3,3-hexafluoro-2-(trifluoromethyl)-2-propanide, prepared bydissolving 33.4 g (0.12 mol) of tri(dimethylamino)sulfoniumdifluorotrimethylsilicate and 24.0 g (0.12 mol) of perfluoroisobutylenein 75 mL of benzonitrile, then pumping out the by-productfluorotrimethylsilane at reduced pressure. The reaction mixture wasevacuated to transfer the volatile reaction product into a cold trap(-78°). Sublimation of the contents of the trap at atmospheric pressuregave 26.11 g (81%) of2-bromo-1,1,1,3,3,3-hexafluoro-2-(trifluoromethyl)propane as a veryvolatile solid: m.p. (sublimation 49°-51°; ¹⁹ F NMR (CDCl₃) δ -67.6 ppm(s).

EXAMPLE B 3,3,3-Trifluoro-2,2-bis(trifluoromethyl)propylbenzene

Benzyl bromide, 18.8 g (0.11 mol), was added dropwise at 10° to asolution of tris(dimethylamino)sulfonium1,1,1,3,3,3-hexafluoro-2-(trifluoromethyl)-2-propanide, prepared bydissolving 24.4 g (0.122 mol) of octafluoroisobutylene and 33.6 g (0.122mol) of tris(dimethylamino)sulfonium difluorotrimethylsilicate in 75 mLof acetonitrile. The reaction mixture was warmed to 25°, stirredovernight, and then poured into ice water. The aqueous mixture wasextracted with ether, and the ether extracts were washed three timeswith water, dried (MgSO₄), and distilled to give 27.35 g (81%) of3,3,3-trifluoro-2,2-bis(trifluoromethyl)propylbenzene as a colorlessliquid, b.p. 53°-54° (12 mm), that solidified on cooling to a whitesolid: m.p. 32°-33°; ¹ H NMR (CDCl₃) δ 3.39 ppm (s, 2H), 7.28 ppm (s,5H); ¹⁹ F NMR (CDCl₃) δ -62.3 ppm (s). Anal. Calcd. for C₁₁ H₇ F₉ : C,42.59; H, 2.28; F, 55.13. Found: C, 42.45; H, 2.23; F, 55.00.

EXAMPLE C2-Bromo-1,1,1,3,3,4,4,5,5,5-decafluoro-2-(trifluoromethyl)pentane

Bromine, 7.99 g (0.5 mol), was added dropwise at 0° to a solution of0.05 mol of tris(dimethylamino)sulfonium1,1,1,3,3,4,4,5,5,5-decafluoro-2-(trifluoromethyl)-2-pentanide, preparedas in Example D (except for the amounts), in 40 mL of benzonitrile. Thereaction mixture was warmed to 25°, and the volatile portion wasdistilled out under reduced pressure, and then redistilled atatmospheric pressure to give 12.8 g (75%) of2-bromo-1,1,1,3,3,4,4,5,5,5-decafluoro-2-(trifluoromethy)pentane as acolorless liquid: b.p. 96.5°-97.2°; ¹⁹ F NMR (CDCl₃) δ -65.2 ppm (m,6F), -81.1 ppm (t, 3F), -105.9 ppm (2F) and -122.6 ppm (2F). Anal.Calcd. for C₆ BrF₁₃ : C, 18.06; F, 61.91. Found: C, 17.90; F, 61.55.

EXAMPLE D2-Chloro-1,1,1,3,3,4,4,5,5,5-decafluoro-2-(trifluoromethyl)pentane

Chlorine, 4.73 g (0.067 mol), was slowly distilled into a solution oftris(dimethylamino)sulfonium1,1,1,3,3,4,4,5,5,5-decafluoro-2-(trifluoromethyl)-2-pentanide, cooledto 0°, prepared by dissolving 20.2 g (0.073 mol) oftris(dimethylamino)sulfonium difluorotrimethylsilicate and 20.0 g(0.0665 mol) of 1,1,1,3,4,4,5,5,5-nonafluoro-2-trifluoromethyl-2-pentenein 75 mL of benzonitrile, then pumping out the by-productfluorotrimethylsilane at reduced pressure. The reaction mixture waswarmed to 25°, and then the most volatile portion was distilled out atreduced pressure and then redistilled at atmospheric pressure to give18.2 g (77%) of the desired chloro compound as a colorless liquid: b.p.84°-85°; ¹⁹ F NMR (CDCl₃) δ -67.7 ppm (t,t, J=12, 10 Hz, 6F), -81.1 ppm(t, J=13 Hz, 3F), -109.4 ppm (m, 2F) and -123.5 ppm (m, 2F). Anal.Calcd. for C₆ ClF₁₃ : C, 20.33. Found: C, 19.55.

EXAMPLE E 3,3,4,4,5,5,5-Heptafluoro-2,2-bis(trifluoromethyl)pentane

Methyl fluorosulfate (7.6 g, 0.0665 mol) was added dropwise at 0° to astirred solution of tris(dimethylamino)sulfonium1,1,1,3,3,4,4,5,5,5-decafluoro-2-(trifluoromethyl)-2-pentanide, preparedby dissolving 20.2 g (0.073 mol) of tris(dimethylamino)sulfoniumdifluorotrimethylsilicate and 20.0 g (0.0665 mol) of1,1,1,3,4,4,5,5,5-nonafluoro-2-trifluoromethyl-2-pentene in 75 mL ofbenzonitrile. The reaction mixture was warmed at 25°, and the mostvolatile portion of the reaction mixture was distilled out under reducedpressure. The distillate was redistilled at atmospheric pressure to give13.27 g (60%) of3,3,4,4,5,5,5-heptafluoro-2,2-bis(trifluoromethyl)pentane as a colorlessliquid: b.p. 88°-89°; ¹⁹ F NMR (CCl₃ F) δ -67.7 ppm (t,t 6F), -81.1 ppm(t, 3F), -110.5 ppm (m, 2F) and -123.7 ppm (m, 2F); ¹ H NMR (CCl₃ F) δ1.72 ppm. Anal. Calcd. for C₇ H₃ F₁₃ : C, 25.17; H, 0.91; F, 73.93.Found: C, 24.88; H, 0.87; F, 73.64.

EXAMPLE F 4,4,5,5,6,6,6-Heptafluoro-3,3-bis(trifluoromethyl)hexane

The procedure described for Example E was repeated except that themethyl fluorosulfate was replaced with 10.28 g (0.067 mol) of diethylsulfate. 4,4,5,5,6,6,6-Heptafluoro-3,3-bis(trifluoromethyl)hexane wasobtained as a colorless liquid: b.p. 104°; ¹⁹ F NMR (CDCl₃) δ -64.1 ppm(t,t, 6F), -80.5 ppm (t, 3F), -107.1 ppm (m, 2F) and -122.6 ppm (2F); ¹H NMR (CDCl₃) δ 1.24 ppm (t, J=7 Hz, 3H) and 2.32 ppm (q, J=7 Hz, 2H).Anal. Calcd. for C₈ H₅ F₁₃ : C, 27.60; H, 1.45; F, 70.95. Found: C,27.99; H, 1.68; F, 70.61.

EXAMPLE G3,3,4,4,5,5,5-Heptafluoro-2,2-bis(trifluoromethyl)pentylbenzene

Benzyl bromide, 4.77 g (0.028 mol), was added dropwise to a solution of15.0 g (0.031 mol) of tris(dimethylamino)sulfonium1,1,1,3,3,4,4,5,5,5-decafluoro-2-(trifluoromethyl)-2-pentanide in 50 mLof acetonitrile at 25° C. and the reaction mixture was stirred overnightand then poured into water. The aqueous mixture was extracted withether, and the ether extracts were dried (MgSO₄) and then distilled togive 7.5 g (66%) of3,3,4,4,5,5,5-heptafluoro-2,2-bis(trifluoromethyl)pentylbenzene as acolorless liquid: b.p. 62°-63° (5 mm); ¹⁹ F NMR (CDCl₃) δ -62.7 ppm(t,t, 6F), -80.7 ppm (t, 3F), -106.3 ppm (m, 2F) and -123.3 ppm (2F); ¹H NMR (CDCl₃) δ 3.52 ppm (s, 2H) and 7.27 ppm (s, 5H). Anal. Calcd. forC₁₃ H₇ F₁₃ : C, 38.07; H, 1.72; F, 60.21. Found: C, 37.82; H, 1.73; F,60.42.

EXAMPLE H4-Nitro-2',2',3',3',4',4',4'-heptafluoro-1',1'-bis(trifluoromethyl)benzeneazobutane

p-Nitrobenzenediazonium hexafluorophosphate, 33.6 g (0.11 mol), wasadded portionwise at 0° to a solution of tris(dimethylamino)sulfonium1,1,1,3,3,4,4,5,5,5-decafluoro-2-(trifluoromethyl)-2-pentanide, preparedby dissolving 31.33 g (0.11 mol) of tris(dimethylamino)sulfoniumdifluorotrimethylsilicate and 34.2 g (0.11 mol) of1,1,1,3,4,4,5,5,5-nonafluoro-2-trifluoromethyl-2-pentene in 75 mL ofacetonitrile. The reaction mixture was warmed to 25°, stirred for 1.5 h,and then poured into 800 mL of ice water. The water was decanted fromthe semi-solid residue, and the residue was washed with ether to give24.5 g (72%) of tris(dimethylaminosulfonium)hexafluorophosphate, m.p.257°-260°. The ether wash was extracted 3X with water, dried (MgSO₄),and evaporated to dryness to give 45.8 g (89%) of the azo compound as abright orange oil: n_(D) 25 1.4292; ¹⁹ F NMR (CDCl₃) δ -63.8 ppm (m,76F), -80.9 ppm (t, 3F), -110.5 ppm (m, 2F) and -124.2 ppm (m, 2F); ¹ HNMR (CDCl₃) δ 8.3 ppm (A₂ B₂ pattern). Anal. Calcd. for C₁₂ H₄ F₁₃ N₃ O₂: C, 30.72; H, 0.86; F, 52.64; N, 8.96. Found: C, 30.84. H, 0.87; F,52.51; N, 8.89.

EXAMPLE I2',2',3',3',4',4',4'-Heptafluoro-1',1'-bis(trifluoromethyl)benzeneazobutane

The procedure described in Example H was repeated, except that anequivalent amount of benzenediazonium hexafluorophosphate was used inplace of the p-nitrobenzenediazonium hexafluoro phosphate. There wasobtained a 72% yield of the azo compound as an orange oil: n_(D) 251.3985; ¹⁹ F NMR (CDCl₃) δ -64.0 ppm (6F), -81.0 ppm (t, 3F), -110.6 ppm(m, 2F) and -124.0 ppm (m, 2F); ¹ H NMR (CDCl₃) δ 7.5 ppm (m, 3H), 7.85ppm (m, 2H). Anal. Calcd. for C₁₂ H₅ F₁₃ N₂ : C, 33.98; H, 1.19; F,58.22; N, 6.61. Found: C, 34.15; H, 1.21; F, 58.22; N, 6.61.

EXAMPLE J1,1,1,3,3,4,4,5,5,5-Decafluoro-2-nitroso-2-(trifluoromethyl)pentane

Nitrosyl chloride, 5.10 g (0.078 mol), was slowly distilled into asolution of tris(dimethylamino)sulfonium1,1,1,3,3,4,4,5,5,5-decafluoro-2-(trifluoromethyl)-2-pentanide, cooledto 0°, prepared by dissolving 23.8 g (0.086 mol) oftris(dimethylamino)sulfonium difluorotrimethylsilicate and 21.5 g(0.0717 mol) of 1,1,1,3,4,4,5,5,5-nonafluoro-2-trifluoromethyl-2-pentenein 100 mL of acetonitrile. The lower blue layer of the reaction mixturewas separated, washed with water, dried (MgSO₄) and distilled to givethe nitroso compound as a deep blue liquid: b.p. 72°-74°; ¹⁹ F NMR(CDCl₃) δ -63.5 ppm (m, 6F), -81.0 ppm (t, 3F), -109.7 ppm (m, 2F) and-124.7 ppm (m, 2F); IR (neat) 1620 cm⁻¹. Anal. Calcd. for C₆ F₁₃ NO; C,20.65; N, 4.01. Found: C, 20.41; N, 4.29.

EXAMPLE K2-Bromo-1,1,1,3,4,4,4-heptafluoro-2,3-bis(trifluoromethyl)butane

Bromine, 4.0 g (0.025 mol) was added dropwise to a solution oftris(dimethylamino)sulfonium1,1,1,3,4,4,4-heptafluoro-2,3-bis(trifluoromethyl)-2-butanide, cooled to0°, prepared by dissolving 6.9 g (0.025 mol) oftris(dimethylamino)sulfonium difluorotrimethylsilicate and 6.3 g (0.021mol) of tetrakis(trifluoromethyl)ethylene in 25 mL of benzonitrile, thenpumping out the by-product fluorotrimethylsilane at reduced pressure.The product was distilled out of the reaction mixture at reducedpressure, and then redistilled at atmospheric pressure to give thebromide as a colorless liquid: b.p. 92°-93°; ¹⁹ F NMR (CDCl₃) δ -63.5ppm (septet, d, J=10, 5 Hz, 6F) and -160.7 ppm (m, 1F). Anal. Calcd. forC₆ BrF₁₃ : C, 18.06; Br, 20.03; F, 61.91. Found: C, 18.14; Br, 19.88; F,61.76.

EXAMPLE L Bromononafluorocyclopentane

Bromine was added to a solution of tris(dimethylamino)sulfonium1,2,2,3,3,4,4,5,5-nonafluorocyclopentanide in benzonitrile, prepared asdescribed in Example 5. Distillation of the reaction mixture gavebromononafluorocyclopentane as a colorless liquid: b.p. 64°-65°; ¹⁹ FNMR (CCl₃ F) δ- 112.4 ppm (d, J=262 Hz, 2F), -136.2 ppm (d, J=262 Hz,2F), -141.4 ppm (m, 1F), -125.4 ppm (d, J=255 Hz, 2F) and -127.8 ppm (d,J=255 Hz, 2F).

EXAMPLE M Polymerization of Methyl Methacrylate withTris(dimethylamino)sulfonium1,1,1,3,3,3-Hexafluoro-2-(trifluoromethyl)-2-propanide

A solution of 60 mg of tris(dimethylamino)sulfonium1,1,1,3,3,3-hexafluoro-2-(trifluoromethyl)-2-propanide in 0.25 mL ofacetonitrile was added to a solution of 0.60 g of methyl trimethylsilyldimethyl ketene acetal in 25 mL of tetrahydrofuran at -78°. Methylmethacrylate, 5.0 mL, was added, and the reaction mixture was warmed to0° at which temperature an exothermic reaction ensued and thetemperature rose to 45°. After cooling to 25°, another 5.0 mL of methylmethacrylate was added. After the exotherm subsided, another 5.0 mL ofmethyl methacrylate was added. Evaporation of the volatile portion gave13.6 g of colorless polymer. Gel permeation chromatographic analysisshowed M_(W) of 3920, M_(n) of 3030.

EXAMPLE N Trimerization of Hexafluoropropene

This example illustrates the utility of a carbanion salt of theinvention in the trimerization of a fluoroolefin. The followingequations depict the formation of the carbanion salt in the first step,followed by reaction of the carbanion salt with excess olefin to producetrimers. The by-products are not shown in the equations. ##STR17##

Hexafluoropropene was passed into a melting ice-cooled flask that hadbeen evacuated and contained a solution of 5.0 g oftris(dimethylamino)sulfonium difluorotrimethylsilicate in 100 mL ofbenzonitrile. Hexafluoropropene pressure of 700 mm of Hg was maintainedfor about 7 h. The lower organic layer was separated and distilled togive 600.0 g of hexafluoropropene trimers as a colorless liquid, bp113°-113.6°. ¹⁹ F NMR analysis indicated that two principal componentsof the trimer mixture were perfluoro(2,4-dimethyl-3-ethyl-2-pentene),57%, and perfluoro(4-methyl-3-isopropyl-2-pentene), 37%.

EXAMPLE O Isomerization of Perfluoro-1-heptene toTrans-Perfluoro-3-heptene

This example illustrates the utility of a carbanion salt of theinvention in the isomerization of a fluoroolefin. The followingequations, wherein TASF is tris(dimethylamino)sulfoniumdifluorotrimethylsilicate, depict the steps involved in theisomerization; carbanion salts of the invention are formed asintermediates. ##STR18##

A mixture of 2.53 g (9.2 mmol) of tris(dimethylamino)sulfoniumdifluorotrimethylsilicate (TASF), 1.60 g (4.6 mmol) ofperfluoro-1-heptene, and 3 mL of dry benzonitrile was stirred and warmedto 40°. The lower organic layer was separated and washed with water togive trans-perfluoro-3-heptene as a colorless liquid: ¹⁹ F NMR (CCl₃ F)δ -81.7 ppm (m, 3F), -118.3 ppm (m, 2F), -123.3 ppm (m, 2F), -124.1 ppm(m, 2F), -126.6 ppm (m, 2F), -89.3 ppm (d,d,t, J=41, 52, 6 Hz, 1F),-105.8 pmm (d,d,t,t, J=117, 52, 28, 3, 1F), and -189.4 ppm (d,d,m,J=117, 41 Hz, 1F).

BEST MODE FOR CARRYING OUT THE INVENTION

The best mode presently contemplated is represented by Examples 1-3 and8, especially Examples 1 and 3.

INDUSTRIAL APPLICABILITY

The carbanion salts of the invention are intermediates in thepreparation of fluorinated compounds which find commercial applicationsin, for example, industrial solvents, dielectric and hydraulic fluids,pharmaceutical products, radio-opaque diagnostic aids, oxygen-carryingliquids for use in artificial blood preparation, and as catalysts in thepolymerization of α,β-unsaturated compounds such as (meth)acrylateesters, polymers from which find well-known industrial uses.

Although the preferred embodiments of the invention have beenillustrated and described, it is to be understood that there is nointent to limit the invention to the precise constructions hereindisclosed, and the right is reserved to all changes and modificationscoming within the scope of the invention as defined in the appendedclaims.

I claim:
 1. Tris(disubstituted amino)sulfonium perfluorocarbanion saltof the formula ##STR19## wherein R¹ through R⁶, each selectedindependently, are C₁ -C₂₀ alkyl, each having at least 2 alpha hydrogenatoms, or any or all of the pairs R¹ and R², R³ and R⁴, and R⁵ and R⁶,each pair selected independently, are --CH₂)₄ or --CH₂)₂ CHY--CH₂)₂,wherein Y is hydrogen or methyl;R_(f) ¹, R_(f) ² and R_(f) ³, eachselected independently, are F, C₁₋₂₀ perfluoroalkyl or C₄₋₁₂perfluorocycloalkyl; and R_(f) ⁴ is C₁₋₂₀ perfluoroalkyl or C₄₋₁₂perfluorocycloalkyl; or any one of the pairs R_(f) ¹ and R_(f) ², R_(f)³ and R_(f) ⁴, R_(f) ¹ and R_(f) ³, and R_(f) ² and R_(f) ⁴, takentogether, is --CF₂)_(n) wherein n is an integer and is 2 to 6; or eachof the pairs R_(f) ¹ and R_(f) ² and R_(f) ³ and R_(f) ⁴, or each of thepairs R_(f) ¹ and R_(f) ³ and R_(f) ² and R_(f) ⁴, taken together, is--CF₂)_(n) wherein n, each selected independently, is an integer and is2 to
 6. 2. Salt of claim 1 wherein R_(f) ¹ is F, R_(f) ² is C₁₋₁₀perfluoroalkyl and each of R_(f) ³ and R_(f) ⁴ is CF₃.
 3. Salt of claim2 wherein each of R¹ -R⁶ is CH₃.
 4. Salt of claim 2 wherein each of thepairs R¹ and R², R³ and R⁴, and R⁵ and R⁶ is --CH₂)₅.
 5. Salt of claim 3wherein R_(f) ² is CF₃ or C₂ F₅.